https://doi.org/10.1140/epja/i2011-11047-x
Regular Article - Experimental Physics
Study of the reaction γp → K+Λ(1520) at photon energies up to 2.65 GeV
1
Physikalisches Institut der Universität Bonn, Bonn, Germany
2
Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Bonn, Germany
3
Institut für Kernphysik, Universität Mainz, Mainz, Germany
Received:
3
November
2010
Revised:
26
January
2011
Published online:
4
April
2011
The reaction γp → K
+
Λ(1520) was measured in the energy range from threshold to 2.65 GeV with the SAPHIR detector at the electron stretcher facility ELSA in Bonn. The Λ(1520) production cross-section was analyzed in the decay modes pK
−, , Σ
±
π
∓, and Λπ
+
π
− as a function of the photon energy and the squared four-momentum transfer t . While the cross-sections for the inclusive reactions rise steadily with energy, the cross-section of the process γp → K
+
Λ(1520) peaks at a photon energy of about 2.0 GeV, falls off exponentially with t , and shows a slope flattening with increasing photon energy. The angular distributions in the t-channel helicity system indicate neither a K nor a K
* exchange dominance. Rather, the rapid change of the angular distribution with energy suggests that, in addition to t -channel K and K* exchange, amplitudes for formation of nucleon resonances in the s-channel play an important role.
© SIF, Springer-Verlag Berlin Heidelberg, 2011